When fire occurs on an aircraft or in a confined space in a building, the toxic fumes generated are a major cause of death. Toxic fumes result from the combustion of construction materials such as plastic and synthetic fibers. Recent studies have shown that in an airplane crash the smoke and fumes generated cause far more fatalities than the impact of the crash alone. It would be desirable to limit the propagation of a fire on an airplane or in a building by covering the room separators with a fire retardant material particularly one that could be applied to the surface like wallpaper.
It has been discovered in accordance with the present invention that a composition comprising exfoliated graphite particles and particles of graphite flake treated with an intercalating agent form a composite which is highly fire retardant. This composite of unexfoliated particles of intercalated graphite and exfoliated graphite particles may be formed into a continuous sheet and rolled to produce a wallpaper like roll of fire retardant material or a floor covering.
The fire retardant composite of the present invention comprises particles of exfoliated flexible graphite and unexfoliated particles of intercalated graphite flake with the relative ratio between the particles being based upon the desired strength and fire retardant properties for the composite.
The method of forming a fire proof flexible graphite wall covering in accordance with the present invention comprises:
contacting particles of graphite flake with an intercalating agent for forming particles of intercalated graphite;
heating particles of intercalated graphite at an elevated temperature to form particles of exfoliated graphite;
combining particles of intercalated graphite with particles of exfoliated graphite in a predetermined proportion; and
compressing the combined particles into a densely compressed graphite sheet .